Easy to do. Do it once and you'll breeze through it after that.
1.) Right click on crop tool, (slice is usually selectable under it (on CS6)), select slice tool.
2.) Right click anywhere in your image, select "Divide Slice" from the menu.
3.) Activate both horizontal and vertical slices, divide slices by pixels or # of cuts. Click ok.
4.) File: Save for Web
5.) Shift + click all tiles you want to save, click save, choose name.

It'll save all of the pieces into a folder called "images" in whichever directory you put it into.